Fusts blog!

BookBooN.com tilbyder gratis e-bøger til studerende, rejsende og erhvervsfolk i PDF format. Ingen registrering nødvendig. Alle bøger er lovlige og skrevet eksklusivt til BookBooN.com. De er financieret af få reklamer i bøgerne.

http://www.free-ebooks.net

Skal registrere sig, og man kan gratis downloade 5 bøger om måneden.

http://www.e-booksdirectory.com/

Gratis og kræver ingen registrering.

http://www.gratis.dk/kategori/gratis-links/computer/e-boeger

Gratis danske bøger.

http://ebookdirectory.com

Lige til at downloade...

http://www.freetechbooks.com/

Online bøger. Ingen registrering nødvendig.

http://www.ebooknetworking.com

Skal registrere sig.

http://www.ufindbook.com/

http://www.ebooklobby.com/

Online bøger. Ingen registrering nødvendig.

20. dec. 2010

Tips til julerengøring

Rengøringstips:

Hvis du har et rodet hjem, skal du gøre følgende:

Opret en ny mappe på din computer.
Navngiv mappen "rod i huset."
Gå hen og tage et glas vin
Højreklik for at slette mappen.
Computeren vil derefter spørge:
"Vil du fjerne rod i huset permanent?"
Klik på JA - knappen.
Placer dine fødder på bordet, drik din vin og bare nyd;)

15. dec. 2010

Alverdens flag

Her finder du alle verdens flag, lige til at downloade.

20. sep. 2010

JavaOne i San Francisco

Så er JavaOne i San Francisco startet, og jeg er så heldig at firmaet har sendt mig herover.

Vi er 41.000 deltagere i år, fra 136 lande (skulle være 59 % af alle lande).

I går holdt Larry Ellison, direktør fra Oracle holdt blandt andet en Keynote, hvor han bare forsøgte at sælge en ny server - gaaaaab.
Før det, holdt HP en salgstale - lige så meget gab!
Keynoten skulle vare 2 timer, men da der var gået 2½ time og good old Larry stadigvæk ikke var færdig, gik jeg :-)

Tilgengæld deltog jeg i en diskussionsgruppe under Java User Group, hvor man bl.a. talte om Concurrency og hvad ville du gøre hvis du kunne bestemme over Java? (Tilføje Clojure eller Aspects?)

Se mere her: http://www.oracle.com/javaonedevelop/index.html

8. jun. 2010

Pythonscript der laver alt om til swing

Et lille Python-script på 111 linier, som laver musikken om til swing.

Hør nogle fantastiske eksempler.

24. maj 2010

Københavns Middelalder Marked

Københavns Middelalder Marked stopper i dag

Se mere her:
http://www.flickr.com/photos/patrickfust/sets/72157624126447398/

22. feb. 2010

En tur ved stranden

5. feb. 2010

Measure your bandwith

Measure your bandwith at IT-borger.

3. feb. 2010

Billeder af huset

Her er et par vinterbilleder af mit sprit nye hus

20. jan. 2010

Fireworks

How did your new years eve look like?

12. nov. 2009

DecimalFormat and rounding off

Why does DecimalFormat round off wrong?

I have this nice method that can format a double.
You may also specify the number of decimals.


public static String formatNumber(double number, int decimals) {
String pattern = "###,##0";
if (decimals > 0) {
  pattern += "." ;
  // Add the wanted number of decimals to the pattern
  for (int i = 0; i < decimals; i++) {
     pattern += "0";
  }
}

// Get the English version of the decimalformatter
DecimalFormat df = (DecimalFormat) NumberFormat.getInstance(
  Locale.ENGLISH);
df.applyPattern(pattern);

return df.format(number);
}

Now I want to run it:


public static void main(String[] args) {
       testNumber(1.5, 0, "2");
       testNumber(2.5, 0, "3");
       testNumber(2.15, 1, "2.2");
       testNumber(2.25, 1, "2.3");
}
public static void testNumber(double number, int decimals, 
      String expected) {
    String formatted = formatNumber(number, decimals);
    System.out.print("Testing " + number + ", decimals " +
      decimals + ", Actual = " + formatted);
    if (formatted.equals(expected)) {
        System.out.println(" Expected = " + expected);
    } else {
        System.out.println(" Expected = " + expected + 
          " <- Not the same!");
    }    
}

The outcome is:


Testing 1.5, decimals 0, Actual = 2 Expected = 2
Testing 2.5, decimals 0, Actual = 2 Expected = 3 <- Not the same!
Testing 2.15, decimals 1, Actual = 2.2 Expected = 2.2
Testing 2.25, decimals 1, Actual = 2.2 Expected = 2.3 <- Not the same!

What???
It looks like it rounds off completely randomly.
If you look closer to the documentation, you'll find that DecimalFormat uses ROUND_HALF_EVEN.
This means that "

Rounding mode to round towards the 'nearest neighbor' unless both neighbors are equidistant, in which case, round towards the even neighbor.

"

But I don't want that, I want it to round up where the fraction is >= 0.5, which is ROUND_HALF_UP, but it seems that you can't change the way DecimalFormat is rounding off, so I've found a way to do it.

If you move the fraction, so the rounding off allways is at the first decimal, you can use Math.round which uses ROUND_HALF_UP, and then set back the correct position for the fraction.

Something like:


 double pow = Math.pow(10, decimals);
 double numberPowed = number * pow;
 number = Math.round(numberPowed) / pow;

Now we can format it using DecimalFormat

But we're not yet homefree, because Math.round is returning a Long, which can't hold big numbers like doubles, so we can only do this trick if the number don't get too big!

The complete method now looks like this:


public static String formatNumber(double number, int decimals) {
    double pow = Math.pow(10, decimals);
    double numberPowed = number * pow;
    // Only do it if the number is not too big
    // Math.round returns the neastest Long, so it must fit 
    // inside a long
    if (numberPowed < Long.MAX_VALUE) {
        number = Math.round(numberPowed) / pow;
    }

    String pattern = "###,##0";
    if (decimals > 0) {
        pattern += "." ;
        // Add the wanted number of decimals to the pattern
        for (int i = 0; i < decimals; i++) {
            pattern += "0";
        }
    }

    // Get the English version of the decimalformatter
    DecimalFormat df = (DecimalFormat) NumberFormat.getInstance(
      Locale.ENGLISH);
    df.applyPattern(pattern);

    return df.format(number);
}

And we'll get the right outcome:


Testing 1.5, decimals 0, Actual = 2 Expected = 2
Testing 2.5, decimals 0, Actual = 3 Expected = 3
Testing 2.15, decimals 1, Actual = 2.2 Expected = 2.2
Testing 2.25, decimals 1, Actual = 2.3 Expected = 2.3

14. aug. 2009

Two convicted in U.K. for refusal to decrypt data

Two convicted in U.K. for refusal to decrypt data

What will come next?
That you must reveal your banking password?

It seems that the authorities want to look in your diary.

I think it should not be possible to force people to reveal such stuff.

It's fine, that the authorities can get a court-order to see your financial transactions.

25. jun. 2009

JQuery rules

JQuery is a Javascript library, that helps you do HTML traversing and manipulation as well as sexy animations.

Here's some examples on how to use JQuery.

27. apr. 2009

Steve's Home Theater

I want to make a home theater - How should I do it?

Well, the answer is here:
Steve's Home Theater